Even when pregnant women have uncomplicated pregnancies and high socioeconomic status, when they experience elevated anxiety, stress or depression these prenatal stressors can alter the structure of the developing fetal brain and disrupt its biochemistry, according to Children’s National Hospital research published online Jan. 29, 2020, in JAMA Network Open.

“Previously we found that 65% of pregnant women who received a diagnosis of fetal congenital heart disease had elevated levels of stress. It’s concerning but not surprising that pregnant women who wonder if their baby will need open heart surgery would feel stress,” says Catherine Limperopoulos, Ph.D., director of the Center for the Developing Brain at Children’s National and the study’s senior author. “In this latest study, we ran the same panel of questionnaires and were surprised to find a high proportion of otherwise healthy pregnant women whose unborn babies are doing well also report high levels of stress.”

Anxiety and depression are the most common mental health problems during pregnancy. To learn more about the implications for the developing fetal brain, the Children’s National research team recruited 119 healthy volunteers with low-risk pregnancies from obstetric clinics in Washington, D.C., from Jan. 1, 2016, to April 17, 2019. The women’s mean age was 34.4 years old. All were high school graduates, 83% were college graduates, and 84% reported professional employment.

The team performed 193 fetal brain magnetic resonance imaging (MRI) sessions between 24-40 weeks gestation and measured the volume of the total fetal brain as well as the cortical gray matter, white matter, deep gray matter, cerebellum, brainstem and hippocampus volumes. On the same day as their MRI visit, the pregnant women completed validated questionnaires to measure maternal stress, anxiety and depression, answering questions such as “how do you feel right now,” “how do you generally feel” as well as the degree of stressful feelings they experienced the month prior.

Elevated maternal depression was associated with decreased creatine and choline levels in the fetal brain

Maternal stress scores decreased with increasing gestational age, while anxiety and depression did not

“We report for the first time that maternal psychological distress may be associated with increased fetal local gyrification index in the frontal and temporal lobes,” says Yao Wu, Ph.D., a research associate working with Limperopoulos at Children’s National and the study’s lead author. “We also found an association with left fetal hippocampal volume, with maternal psychological distress selectively stunting the left hippocampal volumetric growth more than the right. And elevated maternal depression was associated with decreased creatine and choline levels in the fetal brain,” Wu adds.

Late in pregnancy – at the time these women were recruited into the cohort study – the fetal brain grows exponentially and key metabolite levels also rise. Creatine facilitates recycling of adenosine triphosphate, the cell’s energy currency. Typically, levels of this metabolite rise, denoting rapid changes and higher cellular maturation; creatine also is known to support cognitive function. Choline levels also typically rise, marking cell membrane turnover as new cells are generated and support memory, mental focus and concentration.

“These women were healthy, and of high socioeconomic status and educational level, leading us to conclude that the prevalence of prenatal maternal psychological distress may be underestimated,” Limperopoulos adds. “While stress is an everyday reality for most of us, this is different because elevated stress during pregnancy can alter fetal brain programming. Our findings underscore the critical need to universally screen all pregnant women for prenatal psychological distress, even young mothers whose pregnancies wouldn’t otherwise raise red flags.”

Financial support for the research described in this post was provided by the National Institutes of Health under grant No. RO1 HL116585-01 and the Thrasher Research Fund under Early Career award No. 14764.

“We were alarmed by the high percentage of pregnant women with a diagnosis of a major fetal heart problem who tested positive for stress, anxiety and depression,” says Catherine Limperopoulos, Ph.D., director of the Center for the Developing Brain at Children’s National and the study’s corresponding author.

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When a diagnosis of fetal congenital heart disease causes pregnant moms to test positive for stress, anxiety and depression, powerful imaging can detect impaired development in key fetal brain regions, according to Children’s National Hospital research published online Jan. 13, 2020, in JAMA Pediatrics.

While additional research is needed, the Children’s National study authors say their unprecedented findings underscore the need for universal screening for psychological distress as a routine part of prenatal care and taking other steps to support stressed-out pregnant women and safeguard their newborns’ developing brains.

“We were alarmed by the high percentage of pregnant women with a diagnosis of a major fetal heart problem who tested positive for stress, anxiety and depression,” says Catherine Limperopoulos, Ph.D., director of the Center for the Developing Brain at Children’s National and the study’s corresponding author. “Equally concerning is how prevalent psychological distress is among pregnant women generally. We report for the first time that this challenging prenatal environment impairs regions of the fetal brain that play a major role in learning, memory, coordination, and social and behavioral development, making it all the more important for us to identify these women early during pregnancy to intervene,” Limperopoulos adds.

Congenital heart disease (CHD), structural problems with the heart, is the most common birth defect. Still, it remains unclear how exposure to maternal stress impacts brain development in fetuses with CHD.

The multidisciplinary study team enrolled 48 women whose unborn fetuses had been diagnosed with CHD and 92 healthy women with uncomplicated pregnancies. Using validated screening tools, they found:

65% of pregnant women expecting a baby with CHD tested positive for stress

27% of women with uncomplicated pregnancies tested positive for stress

44% of pregnant women expecting a baby with CHD tested positive for anxiety

26% of women with uncomplicated pregnancies tested positive for anxiety

29% of pregnant women expecting a baby with CHD tested positive for depression and

All told, they performed 223 fetal magnetic resonance imaging sessions for these 140 fetuses between 21 and 40 weeks of gestation. They measured brain volume in cubic centimeters for the total brain as well as volumetric measurements for key regions such as the cerebrum, cerebellum, brainstem, and left and right hippocampus.

Maternal stress and anxiety in the second trimester were associated with smaller left hippocampi and smaller cerebellums only in pregnancies affected by fetal CHD. What’s more, specific regions — the hippocampus head and body and the left cerebellar lobe – were more susceptible to stunted growth. The hippocampus is key to memory and learning, while the cerebellum controls motor coordination and plays a role in social and behavioral development.

The hippocampus is a brain structure that is known to be very sensitive to stress. The timing of the CHD diagnosis may have occurred at a particularly vulnerable time for the developing fetal cerebellum, which grows faster than any other brain structure in the second half of gestation, particularly in the third trimester.

“None of these women had been screened for prenatal depression or anxiety. None of them were taking medications. And none of them had received mental health interventions. In the group of women contending with fetal CHD, 81% had attended college and 75% had professional educations, so this does not appear to be an issue of insufficient resources,” Limperopoulos adds. “It’s critical that we routinely to do these screenings and provide pregnant women with access to interventions to lower their stress levels. Working with our community partners, Children’s National is doing just that to help reduce toxic prenatal stress for both the health of the mother and for the future newborns. We hope this becomes standard practice elsewhere.”

Adds Yao Wu, Ph.D., a research associate working with Limperopoulos at Children’s National and the study’s lead author: “Our next goal is exploring effective prenatal cognitive behavioral interventions to reduce psychological distress felt by pregnant women and improve neurodevelopment in babies with CHD.”

Financial support for the research described in this post was provided by the National Institutes of Health under grant No. R01 HL116585-01 and the Thrasher Research Fund under Early Career award No. 14764.

Morphometric and textural analyses of magnetic resonance imaging can point out subtle architectural deviations associated with fetal growth restriction during the second half of pregnancy, a first-time finding that has the promise to lead to earlier intervention.

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Morphometric and textural analyses of magnetic resonance imaging (MRI) can point out subtle architectural deviations that are associated with fetal growth restriction (FGR) during the second half of pregnancy. The first-time finding hints at the potential to spot otherwise hidden placental woes earlier and intervene in a more timely fashion, a research team led by Children’s National Hospital faculty reports in Pediatric Research.

“We found reduced placental size, as expected, but also determined that the textural metrics are accelerated in FGR when factoring in gestational age, suggesting premature placental aging in FGR,” says Nickie Andescavage, M.D., a neonatologist at Children’s National and the study’s lead author. “While morphometric and textural features can discriminate placental differences between FGR cases with and without Doppler abnormalities, the pattern of affected features differs between these sub-groups. Of note, placental insufficiency with abnormal Doppler findings have significant differences in the signal-intensity metrics, perhaps related to differences of water content within the placenta.”

The placenta, an organ shared by the pregnant woman and the developing fetus, delivers oxygen and nutrients to the developing fetus and ferries away waste products. Placental insufficiency is characterized by a placenta that develops poorly or is damaged, impairing blood flow, and can result in still birth or death shortly after birth. Surviving infants may be born preterm or suffer early brain injury; later in life, they may experience cardiovascular, metabolic or neuropsychiatric problems.

Because there are no available tools to help clinicians identify small but critical changes in placental architecture during pregnancy, placental insufficiency often is found after some damage is already done. Typically, it is discovered when FGR is diagnosed, when a fetus weighs less than 9 of 10 fetuses of the same gestational age.

“There is a growing appreciation for the prenatal origin of some neuropsychiatric disorders that manifest years to decades later. Those nine months of gestation very much define the breath of who we later become as adults,” says Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain at Children’s National and the study’s senior author. “By identifying better biomarkers of fetal distress at an earlier stage in pregnancy and refining our imaging toolkit to detect them, we set the stage to be able to intervene earlier and improve children’s overall outcomes.”

The research team studied 32 healthy pregnancies and compared them with 34 pregnancies complicated by FGR. These women underwent up to two MRIs between 20 weeks to 40 weeks gestation. They also had abdominal circumference, fetal head circumference and fetal femur length measured as well as fetal weight estimated.

In pregnancies complicated by FGR, placentas were smaller, thinner and shorter than uncomplicated pregnancies and had decreased placental volume. Ten of 13 textural and morphometric features that differed between the two groups were associated with absolute birth weight.

“Interestingly, when FGR is diagnosed in the second trimester, placental volume, elongation and thickness are significantly reduced compared with healthy pregnancies, whereas the late-onset of FGR only affects placental volume,” Limperopoulos adds. “We believe with early-onset FGR there is a more significant reduction in the developing placental units that is detected by gross measures of size and shape. By the third trimester, the overall shape of the placenta seems to have been well defined so that primarily volume is affected in late-onset FGR.”

Financial support for research described in this post was provided by the National Institutes of Health under award number 1U54HD090257, R01-HL116585, UL1TR000075 and KL2TR000076, and the Clinical-Translational Science Institute-Children’s National.

Children’s National Health System researchers Richard Jonas, M.D., Catherine Bollard, M.B.Ch.B., M.D., and Nobuyuki Ishibashi, M.D., have been awarded a $2.5 million, three-year grant from the National Institutes of Health (NIH) to conduct a single-center clinical trial at Children’s National. The study will involve collaboration between the Children’s National Heart Institute, the Center for Cancer and Immunology Research, the Center for Neuroscience Research and the Sheikh Zayed Institute for Pediatric Surgical Innovation.

The goal of the study will be to optimize brain development in babies with congenital heart disease (CHD) who sometimes demonstrate delay in the development of cognitive and motor skills. This can be a result of multiple factors including altered prenatal oxygen delivery, brain blood flow and genetic factors associated with surgery including exposure to the heart lung machine.

The award will be used to complete three specific aims of a Phase 1 safety study as described in the NIH grant:

Aim 1: To determine the safety and feasibility of delivering allogeneic bone marrow derived mesenchymal stromal cell (BM-MSC) during heart surgery in young infants less than 3 months of age using the heart lung machine. The optimal safe dose will be determined.

Aim 2: To determine the impact of MSC infusion on brain structure using advanced neuroimaging and neurodevelopmental outcomes.

Aim 3: To determine differences in postoperative inflammatory and patho-physiological variables after MSC delivery in the infant with CHD.

“NIH supported studies in our laboratory have shown that MSC therapy may be extremely helpful in improving brain development in animal models after cardiac surgery,” says Dr. Ishibashi. “MSC infusion can help reduce inflammation including prolonged microglia activation that can occur during surgery that involves the heart lung machine.”

In addition the researchers’ studies have demonstrated that cell-based intervention can promote white matter regeneration through progenitor cells, restoring the neurogenic potential of the brain’s own stem cells that are highly important in early brain development.

The Phase 1 clinical trial is being implemented in two stages beginning with planning, regulatory documentation, training and product development. During the execution phase, the trial will focus on patient enrollment. Staff from the Cellular Therapy Laboratory, led by director Patrick Hanley, Ph.D., manufactured the BM-MSC at the Center for Cancer and Immunology Research, led by Dr. Bollard. The Advanced Pediatric Brain Imaging Laboratory, led by Catherine Limperopoulos, Ph.D., will perform MR imaging.

The phase 1 safety study will set the stage for a phase 2 effectiveness trial of this highly innovative MSC treatment aimed at reducing brain damage, minimizing neurodevelopmental disabilities and improving the postoperative course in children with CHD. The resulting improvement in developmental outcome and lessened behavioral impairment will be of enormous benefit to individuals with CHD.

Dietary lipids, already an important source of energy for tiny preemies, also provide a much-needed brain boost by significantly increasing global brain volume as well as increasing volume in regions involved in motor activities and memory, according to research presented during the Pediatric Academic Societies 2019 Annual Meeting.

“Compared with macronutrients like carbohydrates and proteins, lipid intake during the first month of life is associated with increased overall and regional brain volume for micro-preemies,” says Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain at Children’s National and senior author. “Using non-invasive magnetic resonance imaging, we see increased volume in the cerebellum by 2 weeks of age. And at four weeks of life, lipids increase total brain volume and boost regional brain volume in the cerebellum, amygdala-hippocampus and brainstem.”

The cerebellum is involved in virtually all physical movement and enables coordination and balance. The amygdala processes and stores short-term memories. The hippocampus manages emotion and mood. And the brainstem acts like a router, passing messages from the brain to the rest of the body, as well as enabling essential functions like breathing, a steady heart rate and swallowing.

According to the Centers for Disease Control and Prevention, about 1 in 10 U.S. babies is born preterm, or before 37 weeks gestation. Regions of the brain that play vital roles in complex cognitive and motor activities experience exponential growth late in pregnancy, making the developing brains of preterm infants particularly vulnerable to injury and impaired growth.

Children’s research faculty examined the impact of lipid intake in the first month of life on brain volumes for very low birth weight infants, who weighed 1,500 grams or less at birth. These micro-preemies are especially vulnerable to growth failure and neurocognitive impairment after birth.

The team enrolled 68 micro-preemies who were 32 weeks gestational age and younger when they were admitted to Children’s neonatal intensive care unit during their first week of life. They measured cumulative macronutrients – carbohydrates, proteins, lipids and calories – consumed by these newborns at 2 and 4 weeks of life. Over years, Limperopoulos’ lab has amassed a large database of babies who were born full-term; this data provides unprecedented insights into normal brain development and will help to advance understanding of brain development in high-risk preterm infants.

“Even after controlling for average weight gain and other health conditions, lipid intake was positively associated with cerebellar and brainstem volumes in very low birthweight preterm infants,” adds Katherine M. Ottolini, the study’s lead author.

According to Limperopoulos, Children’s future research will examine the optimal timing and volume of lipids to boost neurodevelopment for micro-preemies.

Pediatric Academic Societies 2019 Annual Meeting presentation

“Early lipid intake improves brain growth in premature infants.”

Saturday, April 27, 2019, 1:15-2:30 p.m. (EST)

Katherine M. Ottolini, lead author; Nickie Andescavage, M.D., Attending, Neonatal-Perinatal Medicine and co-author; Kushal Kapse, research and development staff engineer and co-author; and Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain and senior author, all of Children’s National.

“Proton magnetic resonance spectroscopy, a non-invasive imaging technique that describes the chemical composition of specific brain structures, enables us to measure metabolites that may play a critical role for growth and explain what makes breastfeeding beneficial for newborns’ developing brains,” says Catherine Limperopoulos, Ph.D.

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Micro-preemies who primarily consume breast milk have significantly higher levels of metabolites important for brain growth and development, according to sophisticated imaging conducted by an interdisciplinary research team at Children’s National.

“Our previous research established that vulnerable preterm infants who are fed breast milk early in life have improved brain growth and neurodevelopmental outcomes. It was unclear what makes breastfeeding so beneficial for newborns’ developing brains,” says Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain at Children’s National. “Proton magnetic resonance spectroscopy, a non-invasive imaging technique that describes the chemical composition of specific brain structures, enables us to measure metabolites essential for growth and answer that lingering question.”

The research-clinicians enrolled babies who were very low birthweight (less than 1,500 grams) and 32 weeks gestational age or younger at birth when they were admitted to Children’s neonatal intensive care unit in the first week of life. The team gathered data from the right frontal white matter and the cerebellum – a brain region that enables people to maintain balance and proper muscle coordination and that supports high-order cognitive functions.

Each chemical has its own a unique spectral fingerprint. The team generated light signatures for key metabolites and calculated the quantity of each metabolite. Of note:

And the percentage of days infants were fed breast milk was associated with significantly greater levels of both creatine and choline, a water soluble nutrient.

“Key metabolite levels ramp up during the times babies’ brains experience exponential growth,” says Katherine M. Ottolini, the study’s lead author. “Creatine facilitates recycling of ATP, the cell’s energy currency. Seeing greater quantities of this metabolite denotes more rapid changes and higher cellular maturation. Choline is a marker of cell membrane turnover; when new cells are generated, we see choline levels rise.”

Already, Children’s National leverages an array of imaging options that describe normal brain growth, which makes it easier to spot when fetal or neonatal brain development goes awry, enabling earlier intervention and more effective treatment. “Proton magnetic resonance spectroscopy may serve as an important additional tool to advance our understanding of how breastfeeding boosts neurodevelopment for preterm infants,” Limperopoulos adds.

“My best advice to future clinician-scientists is to stay curious and open-minded; I doubt I could have predicted my current research interest or described the path between the study of early oligodendrocyte maturation to in vivo placental development, but each experience along the way – both academic and clinical – has led me to where I am today,” Nickie Andescavage, M.D., writes.

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Too often, medical institutions erect an artificial boundary between caring for the developing fetus inside the womb and caring for the newborn whose critical brain development continues outside the womb.

“To improve neonatal outcomes, we must transform our current clinical paradigms to begin treatment in the intrauterine period and continue care through the perinatal transition through strong collaborations with obstetricians and fetal-medicine specialists,” writes Nickie Andescavage, M.D., an attending in Neonatal-Perinatal Medicine at Children’s National.

Dr. Andescavage’s commentary was published online March 25, 2019, in Pediatrics Research and accompanies recently published Children’s research about differences in placental development in the setting of placental insufficiency. Her commentary is part of a new effort by Nature Publishing Group to spotlight research contributions from early career investigators.

The placenta, an organ shared by a pregnant woman and the developing fetus, plays a critical but underappreciated role in the infant’s overall health. Under the mentorship of Catherine Limperopoulos, Ph.D., director of MRI Research of the Developing Brain, and Adré J. du Plessis, M.B.Ch.B., MPH, chief of the Division of Fetal and Transitional Medicine, Dr. Andescavage works with interdisciplinary research teams at Children’s National to help expand that evidence base. She has contributed to myriad published works, including:

While attending Cornell University as an undergraduate, Dr. Andescavage had an early interest in neuroscience and neurobehavior. As she continued her education by attending medical school at Columbia University, she corroborated an early instinct to work in pediatrics.

It wasn’t until the New Jersey native began pediatric residency at Children’s National that those complementary interests coalesced into a focus on brain autoregulation and autonomic function in full-term and preterm infants and imaging the brains of both groups. In normal, healthy babies the autonomic nervous system regulates heart rate, blood pressure, digestion, breathing and other involuntary activities. When these essential controls go awry, babies can struggle to survive and thrive.

“My best advice to future clinician-scientists is to stay curious and open-minded; I doubt I could have predicted my current research interest or described the path between the study of early oligodendrocyte maturation to in vivo placental development, but each experience along the way – both academic and clinical – has led me to where I am today,” Dr. Andescavage writes in the commentary.

During the last few weeks of pregnancy, certain regions of the fetal brain experience exponential growth but also are more vulnerable to injury during that high-growth period.

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Yao Wu, Ph.D., a research postdoctoral fellow in the Developing Brain Research Laboratory at Children’s National Health System, has received a Thrasher Research Fund early career award to expand knowledge about regions of the fetal brain that are vulnerable to injury from congenital heart disease (CHD) during pregnancy.

CHD, the most common birth defect, can have lasting effects, including overall health issues; difficulty achieving milestones such as crawling, walking or running; and missed days at daycare or school, according to the Centers for Disease Control and Prevention. Brain injury is a major complication for infants born with CHD. Catherine Limperopoulos, Ph.D., director of Children’s brain imaging lab, was the first to provide in vivo evidence that fetal brain growth and metabolism in the third trimester of pregnancy is impaired within the womb.

“It remains unclear which specific regions of the fetal brain are more vulnerable to these insults in utero,” Limperopoulos says. “We first need to identify early brain abnormalities attributed to CHD and understand their impact on infants’ later behavioral and cognitive development in order to better counsel parents and effectively intervene during the prenatal period to safeguard brain health.”

During the last few weeks of pregnancy, certain regions of the fetal brain experience exponential growth but also are more vulnerable to injury during that high-growth period. The grant, $26,749 over two years, will underwrite “Brain Development in Fetuses With Congenital Heart Disease,” research that enables Wu to utilize quantitative, non-invasive magnetic resonance imaging (MRI) to compare fetal brain development in pregnancies complicated by CHD with brain development in healthy fetuses of the same gestational age.Wu will leverage quantitative, in vivo 3-D volumetric MRI to compare overall fetal and neonatal brain growth as well as growth in key regions including cortical grey matter, white matter, deep grey matter, lateral ventricles, external cerebrospinal fluid, cerebellum, brain stem, amygdala and the hippocampus.

The research is an offshoot of a prospective study funded by the National Institutes of Health that uses advanced imaging techniques to record brain growth in 50 fetuses in pregnancies complicated by CHD who need open heart surgery and 50 healthy fetuses. MRI studies are conducted during the second trimester (24 to 28 weeks gestational age), third trimester (33 to 37 weeks gestational age) and shortly after birth but before surgery. In addition, fetal and neonatal MRI measurements will be correlated with validated scales that measure infants’ and toddlers’ overall development, behavior and social/emotional maturity.

“I am humbled to be selected for this prestigious award,” Wu says. “The findings from our ongoing work could be instrumental in identifying strategies for clinicians and care teams managing high-risk pregnancies to optimize fetal brain development and infants’ overall quality of life.”

A team of researchers has found that quantitative magnetic resonance imaging (MRI) can identify pregnancies where placental dysfunction results in fetal growth restriction (FGR), creating the possibility for earlier FGR detection and intervention to augment placental function and thus minimize harm to the fetal brain.

The study, published online in the Journal of Perinatology, reports for the first time that in vivo placental volume is tied to global and regional fetal brain volumes.

Placental insufficiency is a known risk factor for impaired fetal growth and neurodevelopment. It may cause the fetus to receive inadequate oxygen and nutrients, making it difficult to grow and thrive. The earlier placental insufficiency occurs in a pregnancy, the more serious it can be. But detecting a failing placenta before the fetus is harmed has been difficult.

One additional challenge is that a fetus may be small because the placenta is not providing adequate nourishment. Or the fetus simply may be genetically predisposed to be smaller. Being able to tell the difference early can have a lifelong impact on a baby. Infants affected by FGR can experience behavioral problems, learning difficulties, memory and attention deficits, and psychiatric issues as the child grows into adolescence and adulthood.

“Our study proved that MRI can more accurately determine which pregnancies are at greater risk for impaired fetal health or compromised placenta function,” says Nickie Andescavage, M.D., the study’s lead author and a specialist in neonatology and neonatal neurology and neonatal critical care at Children’s National Health System. “The earlier we can identify these pregnancies, the more thoughtful we can be in managing care.”

Dr. Andescavage’s research focus has been how fetal growth affects labor, delivery and postnatal complications.

“Our study proved that MRI can more accurately determine which pregnancies are at greater risk for impaired fetal health or compromised placenta function,” says Nickie Andescavage, M.D., the study’s lead author.

“We don’t have a good understanding of why FGR happens, but we do know it’s hard to identify during pregnancy because often there are no signs,” says Dr. Andescavage. “Even when detected, it’s hard to follow. But if we’re aware of it, we can better address important questions, like when to deliver an at-risk fetus.”

In the study, the team measured placental and fetal brain growth in healthy, uncomplicated pregnancies and in pregnancies complicated by FGR. A total of 114 women participated, undergoing ultrasound, Doppler ultrasound and MRI imaging to measure placental volume and fetal brain volume.

An ultrasound test is often what detects FGR, but the measurements generated by ultrasound can be non-specific. In addition, reproducibility issues with 3D sonography limit its use as a standalone tool for placental assessment. Once FGR is detected via ultrasound, this study showed that complementary MRI provides more accurate structural measures of the fetal brain, as well as more detail and insight into placental growth and function.

“Our team has studied FGR for a few years, using imaging to see that’s happening with the fetus in real time,” says Dr. Andescavage. “The relationship of placental volume and fetal brain development had not been previously studied in utero.”

In pregnancies complicated by FGR, MRI showed markedly decreased placental and brain volumes. The team observed significantly smaller placental, total brain, cerebral and cerebellar volumes in these cases than in the healthy controls. The relationship between increasing placental volume and increasing total brain volume was similar in FGR and in normal pregnancies. However, the study authors write “the overall volumes were smaller and thus shifted downward in pregnancies with FGR.”

In addition, FGR-complicated pregnancies that also showed abnormalities in Doppler ultrasound imaging had even smaller placental, cerebral and cerebellar volumes than pregnancies complicated by FGR that did not have aberrations in Doppler imaging.

Since this study showed that quantitative fetal MRI can accurately detect decreased placental and brain volumes when FGR is present, Dr. Andescavage believes this imaging technique may give doctors important new insights into the timing and possibly the mechanisms of brain injury in FGR. “Different pathways can lead to FGR. With this assessment strategy, we could potentially elucidate those,” she adds.

Using quantitative MRI to identify early deviations from normal growth may create opportunities for future interventions to protect the developing fetal brain. New treatments on the horizon promise to address placental health. MRI could be used to investigate these potential therapies in utero. When those therapies become available, it could allow doctors to monitor treatment effects in utero.

Research reported in this post was supported by the Canadian Institutes of Health Research, MOP-81116; the National Institutes of Health under award numbers UL1TR000075 and KL2TR000076; and the Clinical and Translational Science Institute at Children’s National.

Blood is the conduit through which our cells receive much of what they need to grow and thrive. The nutrients and oxygen that cells require are transported by this liquid messenger. Getting adequate blood flow is especially important during the rapid growth of gestation and early childhood – particularly for the brain, the weight of which roughly triples during the last 13 weeks of a typical pregnancy. Any disruption to blood flow during this time could dramatically affect the development of this critical organ.

Now, a new study by Children’s National Health System researchers finds that blood flow to key regions of very premature infants’ brains is altered, providing an early warning sign of disturbed brain maturation well before such injury is visible on conventional imaging. The prospective, observational study was published online Dec. 4, 2017 by TheJournal of Pediatrics.

“During the third trimester of pregnancy, the fetal brain undergoes an unprecedented growth spurt. To power that growth, cerebral blood flow increases and delivers the extra oxygen and nutrients needed to nurture normal brain development,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National and senior author of the study. “In full-term pregnancies, these critical brain structures mature inside the protective womb where the fetus can hear the mother and her heartbeat, which stimulates additional brain maturation. For infants born preterm, however, this essential maturation process happens in settings often stripped of such stimuli.”

The challenge: How to capture what goes right or wrong in the developing brains of these very fragile newborns? The researchers relied on arterial spin labeling (ASL) magnetic resonance (MR) imaging, a noninvasive technique that labels the water portion of blood to map how blood flows through infants’ brains in order to describe which regions do or do not receive adequate blood supply. The imaging work can be done without a contrast agent since water from arterial blood itself illuminates the path traveled by cerebral blood.

The team studied 98 preterm infants who were born June 2012 to December 2015, were younger than 32 gestational weeks at birth and who weighed less than 1,500 grams. They matched those preemies by gestational age with 104 infants who had been carried to term. The brain MRIs were performed as the infants slept.

Blood flows where it is needed most with areas of the brain that are used more heavily commandeering more oxygen and nutrients. Thus, during brain development, CBF is a good indicator of functional brain maturation since brain areas that are the most metabolically active need more blood.

This figure represents the cerebral blood flow (CBF) maps, corresponding anatomical image aligned to the CBF map, and the regions of interest examined. The scale indicates the quantitative value of the CBF map and is expressed in mL/100g/min. The data are from a preterm infant scanned at term age without evidence of brain injury. The insula (see black arrows in panel ‘D’) may be particularly vulnerable to the added stresses of the preterm infant’s life outside the womb. Credit: M. Bouyssi-Kobar, et al., The Journal of Pediatrics.

“The ongoing maturation of the newborn’s brain can be seen in the distribution pattern of cerebral blood flow, with the greatest volume of blood traveling to the brainstem and deep grey matter,” says Marine Bouyssi-Kobar, M.S., the study’s lead author. “Because of the sharp resolution provided by ASL-MR images, our study finds that in addition to the brainstem and deep grey matter, the insula and the areas of the brain responsible for sensory and motor functions are also among the most oxygenated regions. This underscores the critical importance of these brain regions in early brain development. In preterm infants, the insula may be particularly vulnerable to the added stresses of life outside the womb.”

Of note, compromised regional brain structures in adults are implicated in multiple neurodevelopmental disorders. “Altered development of the insula and anterior cingulate cortex in newborns may represent early warning signs of preterm infants at greater risk for long-term neurodevelopmental impairments,” Limperopoulos says.

Research reported in this post was supported by the Canadian Institutes of Health Research, MOP-81116; the SickKids Foundation, XG 06-069; and the National Institutes of Health under award number R01 HL116585-01.

Children’s National researchers led by Catherine Limperopoulos, Ph.D., demonstrate for the first time that the brains of high-risk infants show signs of functional impairment before they undergo corrective cardiac surgery.

Findings from a Children’s National Health System study of this question suggest the presence of brain dysfunction early in the lives of infants with CHD that may be associated with neurodevelopmental impairments years later.

Using a novel imaging technique, Children’s National researchers demonstrated for the first time that the brains of these high-risk infants already show signs of functional impairment even before they undergo corrective open heart surgery. Looking at the newborns’ entire brain topography, the team found intact global organization – efficient and effective small world networks – yet reduced functional connectivity between key brain regions.

“A robust neural network is critical for neurons to travel to their intended destinations and for the body to carry out nerve cells’ instructions. In this study, we found the density of connections among rich club nodes was diminished, and there was reduced connectivity between critical brain hubs,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National and senior author of the study published online Sept. 28, 2017 in NeuroImage: Clinical. “CHD disrupts how oxygenated blood flows throughout the body, including to the brain. Despite disturbed hemodynamics, infants with CHD still are able to efficiently transfer neural information among neighboring areas of the brain and across distant regions.”

The research team led by Josepheen De Asis-Cruz, M.D., Ph.D., compared whole brain functional connectivity in 82 healthy, full-term newborns and 30 newborns with CHD prior to corrective heart surgery. Conventional imaging had detected no brain injuries in either group. The team used resting state functional connectivity magnetic resonance imaging (rs-fcMRI), a imaging technique that characterizes fluctuating blood oxygen level dependent signals from different regions of the brain, to map the effect of CHD on newborns’ developing brains.

The newborns with CHD had lower birth weights and lower APGAR scores (a gauge of how well brand-new babies fare outside the womb) at one and five minutes after birth. Before the scan, the infants were fed, wrapped snugly in warm blankets, securely positioned using vacuum pillows, and their ears were protected with ear plugs and ear muffs.

While the infants with CHD had intact global network topology, a close examination of specific brain regions revealed functional disturbances in a subnetwork of nodes in newborns with cardiac disease. The subcortical regions were involved in most of those affected connections. The team also found weaker functional connectivity between right and left thalamus (the region that processes and transmits sensory information) and between the right thalamus and the left supplementary motor area (the section of the cerebral cortex that helps to control movement). The regions with reduced functional connectivity depicted by rs-fcMRI match up with regional brain anomalies described in imaging studies powered by conventional MRI and diffusion tensor imaging.

“Global network organization is preserved, despite CHD, and small world brain networks in newborns show a remarkable ability to withstand brain injury early in life,” Limperopoulos adds. “These intact, efficient small world networks bode well for targeting early therapy and rehabilitative interventions to lower the newborns’ risk of developing long-term neurological deficits that can contribute to problems with executive function, motor function, learning and social behavior.”

Children’s National Health System researchers processed H1-MRS data using LCModel software to calculate absolute metabolite concentrations for N-acetyl-aspartate (NAA), choline (Cho) and creatine (Cr). Preterm infants had significantly lower cerebellar NAA (p=<0.025) and higher Cho (p=<0.001) when compared with healthy term-equivalent infants. The area of the brain within the red box is the cerebellum, the region of interest for this study.

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Premature birth, a condition that affects approximately 10 percent of births in the United States, often is accompanied by health problems ranging from difficulties breathing and eating to long-term neurocognitive delays and disabilities. However, the reasons for these problems have been unclear.

In a study published online Aug. 15, 2017 in Scientific Reports, a team of Children’s National Health System clinician-researchers reports that prematurity is associated with altered metabolite profiles in the infants’ cerebellum, the part of the brain that controls coordination and balance. Pre-term infants in the study had significantly lower levels of a chemical marker of nerve cell integrity and significantly higher concentrations of a chemical marker of cellular membrane turnover.

“These data suggest that interrupting the developing fetal brain’s usual growth plan during gestation – which can occur through early birth, infection or experiencing brain damage – might trigger a compensatory mechanism. The infant’s brain tries to make up for lost time or heal injured tissue by producing a certain type of cells more quickly than it normally would,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National and senior study author. “The more sensitive imaging technique that we used also revealed nerve cell damage from brain injuries extends beyond the site of injury, a finding that contrasts with what is found through conventional magnetic resonance imaging (MRI).”

It has long been clear that prematurity – birth before 37 weeks gestation – is accompanied by a number of immediate and long-term complications, from potential problems breathing and feeding at birth to impairments in hearing and sight that can last throughout an individual’s life.

Neurocognitive developmental delays often accompany pre-term birth, many of which can have long-lasting consequences. Studies have shown that children born prematurely are more likely to struggle in school, have documented learning disabilities and experience significant delays in developing gross and fine motor skills compared with children born at full-term.

Several studies have investigated the root cause of these issues in the cerebrum, the structure that takes up the majority of the brain and is responsible for functions including learning and memory, language and communication, sensory processing and movement. However, the cerebellum – a part of the brain that plays an important role in motor control – has not received as much research attention.

In the new study, Limperopoulos and colleagues used a specialized MRI technique that allowed them to parse out differences in which molecules are present in the cerebellum of full-term infants compared with premature infants. Their findings show a variety of differences that could offer clues to explain developmental differences between these two populations – and potentially identify ways to intervene to improve outcomes.

The researchers recruited 59 premature infants, born at 32 or fewer weeks’ gestation, and 61 healthy, full-term infants. Each baby received a special type of MRI known as proton magnetic resonance spectroscopy, or H1-MRS, that measures the concentrations of particular molecules in the brain. The full-term infants had these MRIs shortly after birth; the pre-term infants had them at 39 to 41 weeks gestational age, or around the time that they would have been born had the pregnancy continued to term.

Looking specifically at the cerebellum, the researchers found that the pre-term infants overall had significantly lower concentrations of N-acetyl-aspartate (NAA), a marker of the integrity of nerve cells. They also had significantly higher concentrations of choline, a marker of cell membrane integrity and membrane turnover.

Concentrations of creatine, a marker of stores of cellular energy, were about the same overall between the two groups. However, the researchers found that brain injuries, which affected 35 of the pre-term infants but none of the full-term infants, were associated with significantly lower concentrations of NAA, choline and creatine. Having a neonatal infection, which affected 21 of the pre-term infants but none of the full-term ones, was associated with lower NAA and creatine.

The findings could offer insight into exactly what’s happening in the brain when infants are born pre-term and when these vulnerable babies develop infections or their brains become injured – conditions that convey dramatically higher risks for babies born too early, Limperopoulos says. The differences between the full-term babies and the pre-term ones reflect disturbances these cells are experiencing at a biochemical level, she explains.

Limperopoulos and colleagues note that more research will be necessary to connect these findings to what is already known about developmental problems in pre-term infants. Eventually, she says, scientists might be able to use this knowledge to develop treatments that might be able to change the course of brain development in babies born too early, getting them on track with infants born at term.

“We know that the bodies of pre-term infants demonstrate a remarkable ability to catch up with peers who were born at full-term, in terms of weight and height. Our challenge is to ensure that preemies’ brains also have an opportunity to develop as normally as possible to ensure optimal long-term outcomes,” Limperopoulos says.

Using three-dimensional magnetic resonance imaging, a Children’s National research team that included Catherine Limperopoulos, Ph.D., characterized the shape, volume, morphometry and texture of placentas during pregnancy and, using a novel framework, predicted with high accuracy which pregnancies would be complicated by fetal growth restriction.

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Early in development, cells from the fertilized egg form the placenta, a temporary organ that serves as an interface between the mother and her growing offspring. When things go right, as occurs in the vast majority of pregnancies, the placenta properly delivers nutrients from the mother’s diet and oxygen from the air she breathes to the developing fetus while siphoning away its waste products. This organ also plays important immune-modulating and endocrine roles.

However, in a number of pregnancies, the placenta does not do an adequate job. Unable to effectively serve the fetus, a variety of adverse conditions can develop, including preeclampsia,fetal growth restriction (FGR), preterm birth and even fetal death.

Despite the key role that the placenta plays in fetal health, researchers have few non-invasive ways to assess how well it works during pregnancy. In fact, placental disease might not be suspected until very late.

In a new study, a team of Children’s National Health System research scientists is beginning to provide insights into the poorly understood placenta.

Using three-dimensional (3D) magnetic resonance imaging (MRI), the research team characterized the shape, volume, morphometry and texture of placentas during pregnancy and, using a novel framework, predicted with high accuracy which pregnancies would be complicated by FGR.

“When the placenta fails to carry out its essential duties, both the health of the mother and fetus can suffer and, in extreme cases, the fetus can die. Because there are few non-invasive tools that reliably assess the health of the placenta during pregnancy, unfortunately, placental disease may not be discovered until too late – after impaired fetal growth already has occurred,” says Catherine Limperopoulos, Ph.D., co-director of research in the Division of Neonatology at Children’s National Health System and senior author of the study published online July 22 in Journal of Magnetic Resonance Imaging. “Identifying early biomarkers of placental disease that may impair fetal growth and well-being open up brand-new opportunities to intervene to protect vulnerable fetuses.”

The Children’s research team acquired 124 fetal scans from 80 pregnancies beginning at the 18th gestational week and continuing through the 39th gestational week. Forty-six women had normal pregnancies and healthy fetuses while 34 women’s pregnancies were complicated by FGR, defined by estimated fetal weight that fell below the 10th percentile for gestational age. The placenta was described by a combination of shape and textural features. Its shape was characterized by three distinct 3D features: Volume, thickness and elongation. Its texture was evaluated by three different sets of textural features computed on the entire placenta.

“The proposed machine learning-based framework distinguished healthy pregnancies from FGR pregnancies with 86 percent accuracy and 87 percent specificity. And it estimated the birth weight in both healthy and high-risk fetuses throughout the second half of gestation reasonably well,” says the paper’s lead author, Sonia Dahdouh, Ph.D., a research fellow in Children’s Developing Brain Research Laboratory.

“We are helping to pioneer a very new frontier in fetal medicine,” Limperopoulos adds. “Other studies have developed prediction tools based on fetal brain features in utero. To our knowledge, this would be the first proposed framework for semi-automated diagnosis of FGR and estimation of birth weight using structural MRI images of the placental architecture in vivo. This has the potential to address a sizable clinical gap since we lack methods that are both sufficiently sensitive and specific to reliably detect FGR in utero.”

The research team writes that its findings underscore the importance of future studies on a larger group of patients to expand knowledge about underlying placenta mechanisms responsible for disturbed fetal growth, as well as to more completely characterize other potential predictors of fetal/placental development in high-risk pregnancies, such as genetics, physiology and nutrition.

Critical white matter structures in the brains of babies born prematurely at low birth weight develop more robustly when their mothers breast-feed them, compared with preemies fed formula.

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Breast-feeding offers a slew of benefits to infants, including protection against common childhood infections and potentially reducing the risk of chronic health conditions such as asthma, obesity and type 2 diabetes. These benefits are especially important for infants born prematurely, or before 37 weeks gestation – a condition that affects 1 in 10 babies born in the United States, according to the Centers for Disease Control and Prevention. Prematurely born infants are particularly vulnerable to infections and other health problems.

Along with the challenges premature infants face, there is a heightened risk for neurodevelopmental disabilities that often do not fully emerge until the children enter school. A new study by Children’s National Health System researchers shows that breast-feeding might help with this problem. The findings, presented at the 2017 annual meeting of the Pediatric Academic Societies, show that critical white matter structures in the brains of babies born so early that they weigh less than 1,500 grams develop more robustly when their mothers breast-feed them, compared with preemie peers who are fed formula.

The Children’s National research team used sophisticated imaging tools to examine brain development in very low birth weight preemies, who weighed about 3 pounds at birth.

They enrolled 37 babies who were no more than 32 weeks gestational age at birth and were admitted to Children’s neonatal intensive care unit within the first 48 hours of life. Twenty-two of the preemies received formula specifically designed to meet the nutritional needs of infants born preterm, while 15 infants were fed breast milk. The researchers leveraged diffusion tensor imaging – which measures organization of the developing white matter of the brain – and 3-D volumetric magnetic resonance imaging (MRI) to calculate brain volume by region, structure and tissue type, such as cortical gray matter, white matter, deep gray matter and cerebellum.

“We did not find significant differences in the global and regional brain volumes when we conducted MRIs at 40 weeks gestation in both groups of prematurely born infants,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory and senior author of the paper. “There are striking differences in white matter microstructural organization, however, with greater fractional anisotropy in the left posterior limb of internal capsule and middle cerebellar peduncle, and lower mean diffusivity in the superior cerebellar peduncle.”

White matter lies under the gray matter cortex, makes up about half of the brain’s volume, and is a critical player in human development as well as in neurological disorders. The increased white matter microstructural organization in the cerebral and cerebellar white matter suggests more robust fiber tracts and microarchitecture of the developing white matter which may predict better neurologic outcomes in preterm infants. These critical structures that begin to form in the womb are used for the rest of the person’s life when, for instance, they attempt to master a new skill.

“Previous research has linked early breast milk feeding with increased volumetric brain growth and improved cognitive and behavioral outcomes,” she says. “These very vulnerable preemies already experience a high incidence rate of neurocognitive dysfunction – even if they do not have detectable structural brain injury. Providing them with breast milk early in life holds the potential to lessen those risks.”

The American Academy of Pediatrics endorses breast-feeding because it lowers infants’ chances of suffering from ear infections and diarrhea in the near term and decreases their risks of being obese as children. Limperopoulos says additional studies are needed in a larger group of patients as well as longer-term follow up as growing infants babble, scamper and color to gauge whether there are differences in motor skills, cognition and writing ability between the two groups.

Catherine Limperopoulous, Ph.D., and her colleagues used volumetric MRIs to assess how the ventricles, cerebrospinal fluid and the rest of the fetal brain normally change over time.

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The human brain is not one solid mass. Buried within its gray and white matter are a series of four interconnected chambers, called ventricles, which produce cerebrospinal fluid. These ventricles are readily apparent on the fetal ultrasounds that have become the standard of prenatal care in the United States and most developed countries around the world. Abnormalities in the ventricles’ size or shape – or both – can give doctors an early warning that fetal brain development might be going awry.

But what is abnormal? It is not always clear, says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National Health System. Limperopoulos explains that despite having many variations in fetal ventricles, some infants have completely normal neurodevelopmental outcomes later. On the other hand, some extremely subtle variations in shape and size can signal problems.

On top of these complications are the tools clinicians typically use to assess the ventricles. Limperopoulos explains that most early indications of ventricle abnormalities come from ultrasounds, but the finer resolution of magnetic resonance imaging (MRI) can provide a more accurate assessment of fetal brain development. Still, both standard MRI and ultrasound provide only two-dimensional pictures, making it difficult to quantify slight differences in the volume of structures.

To help solve these problems, Limperopoulos and her colleagues recently published a paper in Developmental Neuroscience that takes a different tack. The team performed volumetric MRIs – a technique that provides a precise three-dimensional measure of structural volumes – on the brains of healthy fetuses to assess how the ventricles, cerebrospinal fluid and the rest of the brain normally change over time. Limperopoulos’ team recently performed a similar study to assess normal volumetric development in the brain’s solid tissues.

Previous studies published on comparable topics typically used information gathered from subjects who initially had clinical concerns but eventually were dismissed from these studies for not having worrisome diagnoses in the end. This might not truly reflect a typical population of pregnant women, Limperopoulos says.

Working with 166 pregnant women with healthy pregnancies spanning from 18 to 40 weeks gestation, the researchers performed volumetric MRIs on their singleton fetuses that covered every week of this second half of pregnancy. This technique allowed them to precisely calculate the volumes of structures within the fetal brain and get an idea of how these volumes changed over time within the group.

Their results show that over the second and third trimester:

The lateral ventricles, the largest ventricles found in the cerebrum with one for each brain hemisphere, grew about two-fold;

The third ventricle, found in the forebrain, grew about 23-fold;

The fourth ventricle, found in the hindbrain, grew about eight-fold;

And the extra-axial cerebrospinal fluid, found under the lining of the brain, increased about 11-fold.

The total brain volume increased 64-fold over this time, with the parenchyma – the solid brain tissue that encompasses gray and white matter – growing significantly faster than the cerebrospinal fluid-filled spaces.

Limperopoulos points out that the ability to measure the growth of the brain’s fluid-filled spaces relative to the surrounding brain tissue can provide critical information to clinicians caring for developing fetuses. In most cases, knowing what is normal allows doctors to reassure pregnant women that their fetus’ growth is on track. Abnormalities in these ratios can provide some of the first signals to alert doctors to blockages in cerebrospinal fluid flow, abnormal development, or the loss of brain tissue to damage or disease. Although the neurodevelopmental outcomes from each of these conditions can vary significantly, traditional ultrasounds or MRIs might not be able to distinguish these possibilities from each other. Being able to differentiate why cerebrospinal fluid spaces have abnormal shapes or sizes might allow doctors to better counsel parents, predict neurological outcomes, or potentially intervene before or after birth to mitigate brain damage.

Catherine Limperopoulos, Ph.D., and colleagues performed the largest magnetic resonance imaging study of normal fetal brains in the second and third trimesters of pregnancy.

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Starting as a speck barely visible to the naked eye and ending the in utero phase of its journey at an average weight of 7.5 pounds, the growth of the human fetus is one of the most amazing events in biology. Of all the organs, the fetal brain undergoes one of the most rapid growth trajectories, expanding over 40 weeks from zero to 100 billion neurons — about as many brain cells as there are stars in the Milky Way Galaxy.

This exponential growth is part of what gives humans our unique abilities to use language or have abstract thoughts, among many other cognitive skills. It also leaves the brain extremely vulnerable should disruptions occur during fetal development. Any veering off the developmental plan can lead to a cascade of results that have long-lasting repercussions. For example, studies have shown that placental insufficiency, or the inability of the placenta to supply the fetus with oxygen and nutrients in utero, is associated with attention deficit hyperactivity disorder, autism, and schizophrenia.

Recent research has identified differences in the brains of people with these disorders compared with those without. Despite the almost certain start of these conditions within the womb, they have remained impossible to diagnose until children begin to show clinical symptoms. If only researchers could spot the beginnings of these problems early in development, says Children’s National Health System researcher Catherine Limperopoulos, Ph.D., they might someday be able to develop interventions that could turn the fetal brain back toward a healthy developmental trajectory.

“Conventional tools like ultrasound and magnetic resonance imaging (MRI) can identify structural brain abnormalities connected to these problems, but by the time these differences become apparent, the damage already has been done,” Limperopoulos says. “Our goal is to be able to pick up very early deviations from normal in the high-risk pregnancy before an injury to the fetus might become permanent.”

Before scientists can recognize abnormal, she adds, they first need to understand what normal looks like.

In a new study published in Cerebral Cortex, Limperopoulos and colleagues begin to tackle this question through the largest MRI study of normal fetal brains in the second and third trimesters of pregnancy. While other studies have attempted to track normal fetal brain growth, that research has not involved nearly as many subjects and typically relied on data collected when fetuses were referred for MRIs for a suspected problem. When the suspected abnormality was ruled out by the scan, these “quasi-controls” were considered “normal” — even though they may be at risk for problems later in life, Limperopoulos explains.

By contrast, the study she led recruited 166 healthy pregnant women from nearby low-risk obstetrics practices. Each woman had an unremarkable singleton pregnancy and ended up having a normal full-term delivery, with no evidence of problems affecting either the mother or fetus over the course of 40 weeks.

At least one time between 18 and 39 gestational weeks, the fetuses carried by these women underwent an MRI scan of their brains. The research team developed complex algorithms to account for movement (since neither the mothers nor their fetuses were sedated during scans) and to convert the two-dimensional images into three dimensions. They used the information from these scans to measure the increasing volumes of the cerebellum, an area of the brain connected to motor control and known to mediate cognitive skills; as well as regions of the cerebrum, the bulk of the brain, that is pivotal for movement, sensory processing, olfaction, language, and learning and memory.

Their results in uncomplicated, full-term pregnancies show that over 21 weeks in the second half of pregnancy, the cerebellum undergoes an astounding 34-fold increase in size. In the cerebrum, the fetal white matter, which connects various brain regions, grows 22-fold. The cortical gray matter, key to many of cerebrum’s functions, grows 21-fold. And the deep subcortical structures (thalamus and basal ganglia), important for relaying sensory information and coordination of movement and behavior, grow 10-fold. Additional examination showed that the left hemisphere has a larger volume than the right hemisphere early in development, but sizes of the left and right brain halves were equal by birth.

By developing similar datasets on high-risk pregnancies or births—for example, those in which fetuses are diagnosed with a problem in utero, mothers experience a significant health problem during pregnancy, babies are born prematurely, or fetuses have a sibling diagnosed with a health problem with genetic risk, such as autism—Limperopoulos says that researchers might be able to spot differences during gestation and post-natal development that lead to conditions such as schizophrenia, attention deficit hyperactivity disorder and autism spectrum disorder.

Eventually, researchers may be able to develop fixes so that babies grow up without life-long developmental issues.

“Understanding ‘normal’ is really opening up opportunities for us to begin to precisely pinpoint when things start to veer off track,” Limperopolous says. “Once we do that, opportunities that have been inaccessible will start to present themselves.”

Premature birth can interrupt a key period of brain development that occurs in the third trimester, which has the potential to impact a child’s long-term learning, language, and social skills. A recent case-control study published in The Journal of Pediatrics applied diffusion tensor magnetic resonance imaging (DTI) to zoom in on the microstructures comprising the critical cerebellar neural networks related to learning and language, and found significant differences between preterm and full-term newborns.

“The third trimester, during which many premature births occur, is typically when the developing cerebellum undergoes its most dramatic period of growth. Normally, the cerebellar white matter tracts that connect to the deep nuclei are rich in pathways where nerve fibers cross. Those connections permit information to flow from one part of the brain to another. It is possible that premature birth leads to aberrant development of these critical neural networks,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National Health System and senior study author.

One in 10 American babies is born prematurely. The brain injury that infants born prematurely experience is associated with a range of neurodevelopmental disabilities, including some whose influence isn’t apparent until years later, when the children begin school. Nearly half of extremely preterm infants go on to experience long-term learning, social, and behavioral impairments.

While conventional magnetic resonance imaging (MRI) can detect many brain abnormalities in newborns, a newer technique called DTI can tease out even subtle injury to cerebral and cerebellar white matter that is not evident with conventional MRI. White matter contains axons, which are nerve fibers that transmit messages. With DTI, researchers can quantify brain tissue microstructure and describe the integrity of white matter.

The research team compared imaging from 73 premature infants born before 32 weeks gestation who weighed less than 1,500 grams with 73 healthy newborns born to mothers who delivered at full term after 37 weeks. After the newborns had been fed, swaddled, and fitted with double ear protection, the imaging was performed as they slept. Nurses monitored their heart rates and oxygen saturation. Their brain abnormalities were scored as normal, mild, moderate, or severe.

All of the full-term newborns had normal brain MRIs as did 44 (60.3 percent) of the preemies.

The preemies had significantly higher fractional anisotropy in the cerebellum, the part of the brain that processes incoming information from elsewhere in the brain, permitting coordinated movement as well as modulating learning, language, and social skills. Alterations in cerebellar microarchitecture was associated with markers for illness severe enough to require surgery – such as correcting abnormal blood flow caused by the failure of the ductus arteriosus to close after birth and to remedy a bowel disease known as necrotizing enterocolitis. The risk factors also are associated with compromised cardiorespiratory function and low Apgar score at five minutes, Limperopoulos and co-authors write. The Apgar score is a quick way to gauge, one minute after birth, how well the newborn withstood the rigors of childbirth. It is repeated at five minutes to describe how the newborn is faring outside of the womb.

“In previous studies, we and others have associated cerebellar structural injury in preterm infants with long-term motor, cognitive, and socio-affective impairments. This is one of the first studies to provide a detailed report about these unexpected alterations in cerebellar microstructural organization,” she adds. “We postulate that the combination of premature birth and early exposure of the immature developing cerebellum to the extrauterine environment results in disturbed micro-organization.”

Additional research is warranted in larger groups of patients as well as long-term follow up of this cohort of newborns to determine whether this microstructural disorganization predicts long-term social, behavioral, and learning impairments.

“A large number of these prematurely born newborns had MRI readings in the normal range. Yet, we know that these children are uniquely at risk for developing neurodevelopmental disabilities later in life. With additional study, we hope to identify interventions that could lower those risks,” Limperopoulos says.

McGill Publications has awarded Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National Health System, with a Medicine Alumni Global Award. She is receiving the School of Physical & Occupational Therapy Alumni Award of Merit. This award is given annually. Read more.

If it does not jeopardize the health of the pregnant mother or her fetus, pregnancies should be carried as close to full term as possible to avoid vulnerable preemies experiencing a delay in brain development, study results published October 28 in Pediatrics indicate.

Some 15 million infants around the world – and 1 in 10 American babies – are born prematurely. While researchers have known that preemies’ brain growth is disturbed when compared with infants born at full term, it remained unclear when preemies’ brain development begins to veer off course and how that impairment evolves over time, says Catherine Limperopoulos, Ph.D., Director of the Developing Brain Research Laboratory at Children’s National Health System and senior study author.

A look at the research

In order to shine a spotlight on this critical phase of fetal brain development, Limperopoulos and colleagues studied 75 preterm infants born prior to the 32th gestational week who weighed less than 1,500 grams who had no evidence of structural brain injury. These preemies were matched with 130 fetuses between 27 to 39 weeks gestational age.

The healthy fetal counterparts are part of a growing database that the Children’s National Developing Brain Research Laboratory has assembled. The research lab uses three-dimensional magnetic resonance imaging to carefully record week-by-week development of the normal in utero fetal brains as well as week-by-week characterizations of specific regions of the fetal brain.

The availability of time-lapsed images of normally developing brains offers a chance to reframe research questions in order to identify approaches to prevent injuries to the fetal brain, Limperopoulos says.

“Up until now, we have been focused on examining what is it about being born too early? What is it about those first few hours of life that leaves preemies more vulnerable to brain injury?” she says. “What is really unique about these study results is for the very first time we have an opportunity to better understand the ways in which we care for preemies throughout their hospitalization that optimize brain development and place more emphasis those activities.”

When the research team compared third-trimester brain volumes, preemies showed lower volumes in the cerebrum, cerebellum, brainstem, and intracranial cavity. The cerebrum is the largest part of the brain and controls speech, thoughts, emotions, learning, as well as muscle function. The cerebellum plays a role in learning and social-behavioral functions as well as complex motor functions; it also controls the balance needed to stand up and to walk. The brainstem is like a router, ferrying information between the brain, the cerebellum, and the spinal cord.

“What this study shows us is that every day and every week of in utero development is critical. If at all possible, we need to keep fetuses in utero to protect them from the hazards that can occur in the extra uterine environment,” she says.

Common, lifelong health conditions like diabetes and hypertension have footprints that can be traced back to the womb. With advanced fetal MRI we seek to understand as much as possible about brain development during the time in utero. Non-invasive imaging technology helps us to identify signs of abnormal fetal development that may facilitate earlier diagnoses of chronic conditions and intervention.

We’re exploiting both the power and safety of MRI to develop ways to pick up early signs and signals in fetuses whose brain development may be veering off in the wrong direction. Using this advanced technology we can begin to detect varying signals or other signs of distress. These signs of distress may appear in the form of a brain chemical imbalance or a structural brain abnormality that is too subtle to be seen by an ultrasound or other scan. We now have the ability to leverage magnetic resonance imaging to examine the brain in utero for even the most subtle derailments that can lead to lifelong consequences.

The first nine months of life, when a fetus is in the womb, is a time of unparalleled growth and a critical time for fetal brain development. As we examine the maturation of the fetal brain, we know that each and every cortical fold represents future function lost or gained and lays the fundamental background or platform from which critical functions will emerge such as language and social and behavioral development.

We are developing technology that can quickly and reliably pick up early signals of a fetal brain that’s going off route to provide the ability to access therapeutic windows that are currently inaccessible. Earlier identification and intervention can improve the quality of life for children and potentially could even reverse the abnormality.

Early identification of fetal distress is critical. To be able to provide an intervention you must first be able to know that a fetus is getting into trouble, and you must be able to identify the problem early enough, in order to intervene before it has already caused injury to the fetus.

New research shows the effectiveness of an Advance Care Planning model developed through participatory research with adolescents in improving palliative care among adult people living with #HIV
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